The present invention relates to an energy absorbing roadway barrier for dissipating kinetic energy upon impact by a moving vehicle and a method of making the energy absorbing roadway barrier.
Media barriers are often disposed between opposing lanes of traffic on a divided highway to prevent head-on collisions. A common form of such media barrier are formed of precast or poured concrete structures somewhat bell-shaped in cross section and having a wide bottom to resist tipping from impact with an automobile or other vehicle and a flared lower section to engage the tire of a vehicle veering from the road into the barrier and a more or less vertical upper section rising to a flattened barrier top. The flared lower section allows the vertical upper section to be set back far enough to provide clearance for the body of the vehicle. Thus, if a vehicle veers into the barrier at a small angle, the barrier acts to turn the car back onto the roadway to prevent a possible head-on collision with vehicles in the lanes of opposing traffic.
Energy absorbing barriers have also been used for vehicular traffic applications including those of a semi-permanent nature which are heavy and difficult to install and can be expensive to maintain. Barriers of this type include fixed guardrails, concrete median barriers, and special structures located in a protected array around highway signs, bridge abutments, and the like. The lighter more portable barriers are less likely to absorb as much impact energy but they are more easily installed for defining temporary traffic lanes, closing off highway construction sites, and establishing pedestrian walkways. Typical highway barriers comprise elongated blocks of concrete arranged end-to-end to intercept vehicles leaving a defined traffic lane which have special shapes to direct the tire hitting the barrier and consequently the vehicle away from crossing the barrier regardless of the shape of the construction. Most barriers are made non-resilient, massive, and heavy in order to possibly stop vehicles. This then becomes more dangerous to the vehicle and to the occupants so that some barriers have been designed to progressively absorb kinetic energy and thereby gradually decelerate a vehicle. Energy absorbing barriers have been suggested having internal chambers filled with gas, liquids, or other fluent materials and sometimes containers, such as barrels filled with sand, while others have depended upon springs or internal shock absorbers. Most of these prior energy absorbing barriers are not readily adapted for interconnection to define a vehicle lane and are characterized by sidewalls undesirably shaped for redirecting the direction of the vehicle tire running onto the barrier or to allow the vehicle tire to climb a portion of the barrier and be re-directed from the barrier.
Typical prior art barriers can be seen in the Zucker U.S. patent for a roadway barrier and restraining cap combination, U.S. Pat. No. 4,502,812, and in the Thompson patent for an energy absorbing barrier, U.S. Pat. No. 4,681,302. The Almer et al. U.S. Pat. No. 4,661,010, is for a concrete block designed to serve as a roadway barrier while the Slaw, Sr. U.S. Pat. No. 4,605,336, is a joint construction of concrete members for joining barrier-type members end-to-end. The Hahne U.S. Pat. No. 4,641,993, is a highway barrier with level internal ducts and a construction method. The Younker U.S. Pat. No. 3,678,815, is a concrete structural member and a method of forming the same. The Stewart U.S. Pat. No. 817,282, is a composition fence post having a barrier-like shape while the Chiodo U.S. Pat. No. 4,869,617, is a portable highway barrier which can be filled with water or other fluid. The Fitch U.S. Pat. No. 3,643,924 is a highway safety device for deflecting or decelerating a vehicle. The Gertz et al. U.S. Pat. No. 4,352,484, is a shear action and compression energy absorber for dissipating the energy of the impact of a vehicle while the Forster et al. U.S. Pat. No. 4,435,106, is a roadway barrier for directing the wheels of a vehicle impacting the barrier and has a steep convex rise portion. The Diana U.S. Pat. No. 4,665,673, is a monolithic surface ornamentation of precast reinforced concrete wall which includes barrier designs while the Duckett U.S. Pat. No. 4,806,044, is an anti-crash lane barrier with a self-centering hinge.
Applicant's prior patents dealing with lightweight concrete construction or components can be seen in U.S. Pat. No. 4,011,355 for a lightweight composition and method using coated polystyrene beads in a concrete mixture to make a lightweight concrete and in the U.S. Pat. No. 4,355,484 for a hydroponic tray or method of manufacture which provides for a floating hydroponic system using lightweight concrete and in U.S. Pat. No. 4,468,885 for a hydroponic system with floating plant trays and precast concrete sidewalls. The method for making the material is derived from Applicant's prior U.S. Pat. No. 4,011,355. The present improved process is especially adapted for use in the recycling of materials, such as chopped up rubber tires and chopped up used polystyrene which thus serves the purpose of reinforcements and strengthening lightweight barrier members while recycling used materials which are otherwise difficult to recycle and providing an energy absorbing barrier portion supported by a high density reinforced core anchored with steel anchors.